In ophthalmic surgery, adequate visualization of interior portions of the eye is critical to the success of the surgical procedure. The development of endoillumination has greatly improved the way surgeons are able to visualize the interior portions of the eye. One form, chandelier lighting, provides a stationary and dispersed form of light, which may be focused or diffused, from an anterior location. Most common ophthalmic surgery procedures involve making three stab incisions (i.e., sclerotomy) for accessing the eye through the vitreous chamber. One of these incisions is used for insertion of the illuminator. A second incision is ultimately used for insertion of an infusion cannula, which is used to introduce fluids to prevent collapse and otherwise maintain the integrity of the eye. A third incision is made in the eye for insertion of the specific surgical instruments to be used for performing the surgery. To minimize the invasiveness of this type of surgery, it is desirable to reduce the size of the incisions accommodating instruments ranging from 18 g to 42 g.
There are various types of illuminators employed in ophthalmic surgery. These illuminators typically employ an optical fiber having a flexible elongate length with opposed proximal and distal ends. The optical fiber is usually encased in an elongate tubular sleeve with some form of cladding. The proximal end of the optical fiber is secured to a connector adapted for coupling to a corresponding illumination light source for supplying the illumination light through the optical fiber. The distal end of the optical fiber is inserted through an incision in the eye and the illumination light emitted therefrom is dispersed throughout the vitreous chamber of the eye.
Some problems have been experienced with use of prior art illuminators. For example, the optical fiber and sleeve typically exhibits a relatively high degree of resistance to bending or stiffness. When the distal end of the optical fiber is inserted vertically into the eye, the collective weight of the remaining length of the optical fiber and sleeve is directed upon the distal end causing some degree of shear force. This weight generates a bending moment or torque on the optical fiber and sleeve and causes undue stress at the point of contact with the eye (i.e., incision) and potentially affecting the positioning and integrity of the eyeball itself.
Another problem involves the undesirable tendency of the distal end of the optical fiber where the light is emitted to inadvertently slide out from the eye during the surgical procedure. This requires halting of the surgery to re-insert the optical fiber, which can be problematic if the incision seals on its own and becomes not readily detectable or the optical fiber becomes contaminated.
Accordingly, there is a need for a microsurgical instrument adapted for providing illumination light that overcomes the problems discussed above. In particular, there is a need for a microsurgical instrument designed to reduce or minimize the bending moment on the site of a surgical incision. There is a further need to provide a microsurgical instrument configured for enhanced securement to the surgical incision, thereby substantially reducing the incidence of inadvertent slippage or withdrawal therefrom.